Conventionally, surveys or polls are a series of questions on a form presented to individuals, called voters, to sample the views of people in a given region or country for political, commercial or entertainment purposes. Surveys are typically conducted either in person, mail, or via telephone to a great number of individual voters. With the development of the Internet and its growing widespread use, surveys can now be taken by persons at their computer. For example, a system for conducting surveys over the Internet is described in U.S. patent application Ser. No. 09/243,064, filed Feb. 2, 1999. Often surveys are used to test concepts, such as the packaging of a new food product, before companies make an investment in the product or to determine the best way to advertise the product. It is important in concept test surveys that the information used to convey the content of the concept be prevented from view by competitors who could use the information to the disadvantage of the company supporting the survey. This is easy in conventional surveys where the viewed information is provided in a protected environment of in-person polling. However, in surveys conducted over the Internet, the environment of the typical web browser software enables a user easily to copy downloaded information of a survey to a storage file, E-mail, or printer. Thus, it would be desirable to conduct a survey over the Internet in which content information of the survey is protected from unauthorized viewing or copying.
Complicated systems for downloading digital works to computer systems have been developed capable of providing billing and payment to the owners of the digital works based on usage, such as copying or displaying, which may be metered. For example, U.S. Pat. Nos. 5,629,980, 5,638,443, and 5,715,403 describe a system for controlling the distribution and use of digital works in which usage rights are permanently attached to each digital work stored in repositories, and rendering systems receiving a digital work have access to the work in accordance with the usage rights attached to the work. In another example, U.S. Pat. No. 5,982,891 provides a system for virtual distribution to electronic appliances, such as computers, to enable payment for use, and reporting of use, of content distributed to such electronic appliances. The electronic appliance can have a secure processing unit to provide a processing environment offering tamper resistance. In the electronic appliance, access to distributed content is not allowed unless control information, rules and controls, for that content is present at the appliance specifying usage. These systems, which may use encryption/decryption techniques, are complex in order that they can support traditional commercial distribution and transaction methods for digital works. Unauthorized copying of digital works is primarily prevented by the usage or control information which must be present, or permanently attached, to digital works.